In this uneven but well-acted mystery story with a few gaps in the plot here and there, Alec Guiness plays a double role. He is John Barratt, a British teacher on vacation in France who is conned into taking on another identity. The identity he assumes is that of his double, Count Jacques de Gue, who has none of John's upright, moral character. Once ensconced as the Count, John discovers that the Count's mother (Bette Davis) is addicted to morphine, his wife (Irene Worth) believes he is out to kill her, and the Count's brother-in-law (Peter Bull) is embezzling funds away from the family business. And those are just a few of his problems, alleviated somewhat by his mistress (Nicole Murray). Once John realizes how decadent and immoral the Count really is he feels duty-bound to challenge him to a duel.